In such a cine camera the film must be transported intermittently, by the usual reciprocating-claw mechanism, past the exposure gate and at substantially constant speed past the recording head. An advantageous constant-speed feeder comprises a driven capstan and a pinch roller serving to clamp the film between itself and the capstan. Means for co-ordinating the two drives have been described in our prior application referred to above and in our copending application Ser. No. 669085 filed Mar. 23, 1976 as a continuation-in-part thereof, now U.S. Pat. No. 4,003,643.
As further disclosed in that prior application and in the aforementioned continuation-in-part thereof, as well as in our copending application Ser. No. 669,338 filed Mar. 22, 1976 as another continuation-in-part of that prior application, the pinch roller and the capstan should be widely separated during the loading of the camera with a sound-film cassette in order to provide the necessary clearance for the insertion of an unsupported stretch of film therebetween; upon such insertion, and prior to the operation of a release button or trigger to start the film drive, a feeler discriminating between silent-film and sound-film cassettes causes the pinch roller to move closer to the capstan in the presence of a cassette of the sound-film type to engage the film.